x y
11 13
15 9
19 15
21 7
25 11
29 5
x y
11 13
15 9
19 15
21 7
25 11
29 5
\(\ \)
\(\bar{X}=20\);
\(\bar{Y}=10\);
\(S_X=6.5\);
\(S_Y=3.7\)
The covariance measures how much each value deviates from the mean. Notice for two of the data points in the upper left corner of the graph, the X value is below average and the Y value is above average.
There is only one data point in the lower left corner, representing a data value where both X and Y are below average.
There are two points in the lower right corner, representing a data value where X is above average and Y is below average.
Finally, there is a single point in the upper right corner, representing a data value where both X and Y are above average.
x_centered y_centered product
9 -5 -45
1 -3 -3
-5 -1 5
5 1 5
-9 3 -27
-1 5 -5
\(\ \)
---
data_dictionary:
sleep.txt
source:
This dataset is part of the Austrasian Data and
Story Library (OZDASL). Please cite this data as
Smyth, GK (2011). Australasian Data and Story
Library (OzDASL). http://www.statsci.org/data.
The data comes originally from Allison, T., and
Cicchetti, D. V. (1976). Sleep in mammals.
ecological and constitutional correlates.
Science 194 (November 12), 732-734.
description:
This dataset has information about sleep patterns
in 62 common mammals, along with other information
that might help you understand what influences
variations in sleep.
download:
text-format: http://www.statsci.org/data/general/sleep.txt
additional-information: http://www.statsci.org/data/general/sleep.html
copyright:
There is no information about the copyright for this
dataset. You should, however, be able to use this
data for individual educational purposes under the
Fair Use guidelines of U.S. copyright law.
format:
delimiter: tab
varnames: included in the first row of data
missing-value-code: NA
rows: 62
columns: 11
vars:
Species:
label: Species of mammal
BodyWt:
label: Body weight
unit: kg
BrainWt:
label: Brain weight
unit: g
NonDreaming:
label: Time spent in non-dreaming sleep
unit: hours
Dreaming:
label: Time spent in dreaming sleep
unit: hours
TotalSleep:
label: Total time spent in sleep
unit: hours
LifeSpan:
unit: years
Gestation:
unit: days
Predation:
scale: likert
range: 1-5
Exposure:
scale: likert
range: 1-5
Danger:
scale: likert
range: 1-5
---